def add(a, b):
    a += b
    return a

class Company:
    def __init__(self, name, staffs = []):
        self.name = name
        self.staffs = staffs
    def add(self, staff_name):
        self.staffs.append(staff_name)

    def remove(self, staff_name):
        self.staffs.remove(staff_name)

if __name__ == '__main__':

    com1 = Company("com1", ["bobby1", "bobby2"])
    com1.add("bobby3")
    com1.remove("bobby1")
    print(com1.staffs)

    com2 = Company("com2")
    com2.add("bobby")
    print(com2.staffs)

    com3 = Company("com3")
    com3.add("bobby5")
    print(com2.staffs)
    print(com3.staffs)
    print(com2.staffs is com3.staffs)

    a = 1
    b = 2

    a = [1, 2]
    b = [3, 4]

    a = (1, 2)
    b = (3, 4)

    c = add(a,b)
    print(c)
    print(a, b)